Um…the fact that nightmarishly evil people have hoarded almost all of them, making them virtually unbeatable?
Keeping a mountain afloat requires a variation on the same fundamental thing that powers the Wards, yes. All will be clear by Game 4. 
For now I’ll just say that it’s a (non-obvious) ramification of stuff I’ve already introduced, not a radically new feature of the gameworld; it’s not an alternative fuel for Theurgy that could displace aether; and it’s useless for all the stuff I listed that’s not in the 4% category.